Approximate the work for the following reaction at 300k. CH4 (g) + 2O2 (g) → CO2 (g) + 2H2O (l)

a. -2.5kJ
b. -7.5 kJ
c. 5 kJ
d. -5 kJ
e. 7.5 kJ
f. 0 kJ
g. 2.5 kJ